Chapter 3. Monitoring CodeReady Workspaces

Prerequisites

• CodeReady Workspaces is exposing metrics on port 8087. See Enabling and exposing codeready-workspaces metrics.
• Prometheus 2.9.1 or higher is running. The Prometheus console is running on port 9090 with a corresponding service and route. See First steps with Prometheus.

Procedure

• Configure Prometheus to scrape metrics from the 8087 port:

  Prometheus configuration example

  apiVersion: v1
  kind: ConfigMap
  metadata:
    name: prometheus-config
  data:
    prometheus.yml: |-
        global:
          scrape_interval:     5s             1
          evaluation_interval: 5s             2
        scrape_configs:                       3
          - job_name: 'che'
            static_configs:
              - targets: ['[che-host]:8087']  4

  1

  Rate, at which a target is scraped.

  2

  Rate, at which recording and alerting rules are re-checked (not used in the system at the moment).

  3

  Resources Prometheus monitors. In the default configuration, there is a single job called che-host, which scrapes the time series data exposed by the CodeReady Workspaces server.

  4

  Scrape metrics from the 8087 port.

Verification steps

• Use the Prometheus console to query and view metrics.

  Metrics are available at: http://<che-server-url>:9090/metrics.

  For more information, see Using the expression browser in the Prometheus documentation.

Additional resources

• First steps with Prometheus.
• Configuring Prometheus.
• Querying Prometheus.
• Prometheus metric types.

• che-core-metrics-core — contains core metrics module
• che-core-api-metrics — contains metrics that are dependent on core CodeReady Workspaces components, such as workspace or user managers

Procedure

• Create a class that extends the MeterBinder class. This allows to register the created metric in the overridden bindTo(MeterRegistry registry) method.

  The following is an example of a metric that has a function that supplies the value for it:

  Example metric

  public class UserMeterBinder implements MeterBinder {
  
    private final UserManager userManager;
  
    @Inject
    public UserMeterBinder(UserManager userManager) {
      this.userManager = userManager;
    }
  
    @Override
    public void bindTo(MeterRegistry registry) {
      Gauge.builder("che.user.total", this::count)
          .description("Total amount of users")
          .register(registry);
    }
  
    private double count() {
      try {
        return userManager.getTotalCount();
      } catch (ServerException e) {
        return Double.NaN;
      }
    }

  Alternatively, the metric can be stored with a reference and updated manually in some other place in the code.

Additional resources

• Metric and label naming for Prometheus
• Metric types for Prometheus